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The Voyager 1 spacecraft, launched in 1977, has reached a new region at the edge of the solar system called the "magnetic highway."

This is exciting because scientists think it is the final region before the space probe enters interstellar space, which is the space between solar systems. Once Voyager 1 reaches this area, it will become the first man-made object to exit our solar system.

Scientists know that Voyager 1 has crossed a new zone in space for a couple of reasons.

Our sun blows out a stream of charged particles, called solar wind, that form a bubble around our solar system known as the heliosphere. Interstellar space also emits charged particles called cosmic rays, but these are stopped from entering our atmosphere by the Sun's magnetic field.

In June, new data showed that intensity of energetic particles from inside the heliosphere was slowing down, while the intensity from charged particles near the outer shell of the bubble, known as the heliosheath, was getting stronger.

The particle changes were a strong indication that Voyager 1 was leaving the heliosphere. But there was one problem. If the spacecraft was in fact nearing interstellar space, then the magnetic field of the Sun should also change direction as it's acted on by the interstellar magnetic field. That did not happen.

This led researchers to believe that Voyager 1 had entered a region of space that had never been seen before. In this new frontier, the magnetic field lines of the Sun connected to the interstellar field, in turn, creating a "highway" that allowed particles from the Sun to zoom out and particles from interstellar space to stream in.

"We believe [the magnetic highway] is the last leg of our journey to interstellar space," Voyager project scientist Edward Stone said in a statement. "Our best guess is it's likely just a few months to a couple years away. The new region isn't what we expected, but we've come to expect the unexpected from Voyager."